The lone survivor in the fatal North Memorial Health medical helicopter crash at the Brainerd Lakes Regional Airport last month told investigators that foggy conditions forced the pilot to make a "go-around" moments before it spun and hit the ground during an attempted landing.

The account from paramedic Joshua Duda, 42, of Pillager, Minn., was disclosed in a preliminary report released this week by the National Transportation Safety Board (NTSB) in connection with the June 28 crash that killed pilot Tim McDonald, 44, a Minnesota native who lived in Danbury, Wis., and nurse Deb Schott, 58, from Lester Prairie, Minn.

The AgustaWestland A109 helicopter went down about 1 a.m. June 28 at the airport on returning from delivering a patient to North Memorial Health Hospital in Robbinsdale.

Moments after descending from a cruising altitude of 6,000 feet, McDonald began his approach.

Duda could see the runway and its lights "below a thin fog layer during the approach to landing," the preliminary report read. "[Duda] recalled the pilot remarking that the weather conditions were foggy, and they would need to go around. He subsequently noticed the helicopter spin to the right and impact the ground."

Duda was taken to Essentia Health-St. Joseph's Medical Center in Brainerd for treatment of serious injuries.

Damage to the helicopter led investigators to determine that the aircraft made a "high velocity vertical descent" before impact, the report added.

Several flight-data recording devices were recovered from the scene and turned over to the NTSB for examination by investigators.